The Anglo-American philosopher, Stephen Toulmin, has just died, aged 87. One of the areas to which he made major contributions was argumentation, the theory of argument, and his work found and finds application not only in philosophy but in computer science.

For instance, under the direction of John Fox, the Advanced Computation Laboratory at Europe’s largest medical research charity, Cancer Research UK (formerly, the Imperial Cancer Research Fund) applied Toulmin’s model of argument in computer systems they built and deployed in the 1990s to handle conflicting arguments in some domain. An example was a system for advising medical practitioners with the arguments for and against prescribing a particular drug to a patient with a particular medical history and disease presentation. One company commercializing these ideas in medicine is Infermed. Other applications include the automated prediction of chemical properties such as toxicity (see for example, the work of Lhasa Ltd), and dynamic optimization of extraction processes in mining.

For me, Toulmin’s most influential work was was his book Cosmopolis, which identified and deconstructed the main biases evident in contemporary western culture since the work of Descartes:

A bias for the written over the oral

A bias for the universal over the local

A bias for the general over the particular

A bias for the timeless over the timely.

Formal logic as a theory of human reasoning can be seen as example of these biases at work. In contrast, argumentation theory attempts to reclaim the theory of reasoning from formal logic with an approach able to deal with conflicts and gaps, and with special cases, and less subject to such biases. Norm’s dispute with Larry Teabag is a recent example of resistance to the puritanical, Descartian desire to impose abstract formalisms onto practical reasoning quite contrary to local and particular sense.

Another instance of Descartian autism is the widespread deletion of economic history from graduate programs in economics and the associated privileging of deductive reasoning in abstract mathematical models over other forms of argument (eg, narrative accounts, laboratory and field experiments, field samples and surveys, computer simulation, etc) in economic theory. One consequence of this autism is the Great Moral Failure of Macroeconomics in the Great World Recession of 2008-onwards.

3 Responses to “Vale: Stephen Toulmin”

I plead not guilty! I’m well aware that formal symbolic logic is of limited value in most human discourse. In most practical arguments, such universal, general, timeless, logical techniques do not produce anything which isn’t fairly obvious anyway. (Our subconsiouses seem to be ahead of the game on that score.)

That isn’t to say that such rules are not valid, though. Framing a question suitably and identifying its precise assumptions and conclusions can lift it from its local situation into the timeless (in my view, anyway). Usually though, this framing is enough on its own to make the conclusion fairly obvious. The law of deduction, or whatever, is not then especially useful as an analytical tool – I’m not claiming otherwise.

When all goes smoothly, such general logical architecture goes largley unnoticed, as it should. My point – misrepresented in the post you link to – is that if you do try to exploit it to force through conclusions which are to any extent non-obvious, it is quite possible to make a mess of it, and this may be simply your mistake, rather than illustrative of the unsuitability of the tools, as Norm demonstrated.

But what can “validity” mean (line 1 of para 2) if not all the assumptions of the abstract formalism ever apply in any real-world domain?

I am questioning your entire enterprise, especially since De Morgan’s laws are not even the only possible rules (ie, the axioms on which they are based give rise to different rules if different axioms are chosen). In other words, there are many formal logics, not just one, so even without any experience of the world, a reasonable person would question your application of this one logic to human reasoning. This subject is too long for a comment, so I’ll respond with another post in a few days.

My original post to Norm had two purposes. The first was to show that his argument was hopelessly mangled – his interpretation of what it means to metaphorically “chuck a thing in a skip” was so broad as to be inapplicable in any conceivable scenario. I would be comforted if you could acknowledge this point.

The second, and minor point – which I now regret raising as it is threatening to muddy the water with a lot of unnecessary technicalities – was that his interpretation of metaphorically “chucking a thing in a skip” did not even correspond to the standard procedure of logical negation. If this phrase was to have a simple, clear-cut logical meaning – Norm’s assumption not mine – then surely it should be that, should it not? But I make no claims that it should have such a straightforward interpretation. In fact it obviously does not.

So, if we are to discuss the applicability or otherwise of De Morgan’s laws to political disputes, then I look forward to it. But I request that you don’t misrepresent my position. In particular, it is inaccurate to suggest that I am trying to inflict some nightmarish formalistic ‘enterprise’ on everyone, with Norm playing the role of the heroic resistance and defender of commonsense.

That may be how he is trying to frame the debate, but in fact the contrary is true. If I am to be taken to task for applying broad, abstract principles of logic to a political dispute, then it seems fair that he should recieve the same treatment (with perhaps added force), since it was he who first introduced them into the discussion!